Investigations of internal gravity waves using three vertically directed closely spaced wind profilers

A network of three wind profilers spaced about 5 km apart was operated in southern France during the Alpine Experiment (ALPEX) program. The wind profilers measured vertical motions, and the experiment was designed to study traveling internal waves by comparing the vertical velocity fluctuations observed at each station. The measured phase velocities, together with the observed periods, were used to deduce the horizontal wavelength of the waves. Only a relatively few cases of monochromatic waves could be identified using this array. Most of the waves that were detected had phase velocities opposite to the prevailing wind and had the speeds required to cause trapping as the intrinsic frequency was Doppler shifted upward to the Brunt‐Väisälä frequency.